EB48 2.1 Center Rear Drive Shaft Problem

[phm14]

Strange issue with the center rear shaft-2nd trip to the track, and the press fit cross pin (center diff side) walked out, so suddenly, no drive. Driving was hard on the car, as I'm re-learning track driving. Also broke a drivers front control arm, bent that hinge pin, and broke a front shock stand off. Anyone else had this press fit cross pin fall out? Not sure if anything preventative measures could be taken, so only fix is to press in another pin, or replace the assembly.

 

[Billl DeLong]

I don't run TEKNO anymore, but I have experienced this same problem with other brands in the past, I would chalk it up to a tolerance issue with either the pin or the shaft.

My workaround is to degrease the metal with an alcohol swab and apply a gel based red thread lock in the shaft opening before pressing in a new pin and that usually works fine:

https://www.amazon.com/Vibratite-Permanent-Anaerobic-Threadlocker-Milliliter/dp/B008RMTKUO

*** You'll need to apply heat later if you want to press a replacement pin

 

[Skynet5]

I have had the pin from a driveshaft walkout. Our Uk distributor sent out a replacement. RPRC are great here so it was no issue. Although I’m sure any tekno distributor will help to the same level.

I’ve never broken an arm. But i bent plenty of hinge pins and cracked the metal collar in the arms (which do seem unreasonably expensive).

That all stopped happening once I got better driving. Although I do have spares, as over time the knocks build up and they bend a little still.

I’ve also broken one standoff, but that was after a lot of beginner crashes, and also cracked the gearbox, and bent the tower.

Ignoring the driveshaft issue, which I think could be fixed with some red threadlock, those are parts that break.

I was terrible at taking jumps and causing proper chaos. lol. Surprise the parts didn’t break sooner tbh.

But based on the damage I see from other brands, Tekno is solid in comparison. Xray WRC Mugen all fair much worse.

 

[phm14]

Thanks for the info, guys. Contacted Techno, and they requested proof of purchase, and a pic. I'll get around to that, but do think it's time to pick up a pin press, and some dog bone pins. Can anyone offer an opinion on which is more durable, Tekno or Kyosho? I used to run the Kyosho 7.5 nitro, then e buggy. Can't recall being able to break those, 3 times in one day...

 

[phm14]

I don't run TEKNO anymore, but I have experienced this same problem with other brands in the past, I would chalk it up to a tolerance issue with either the pin or the shaft.

My workaround is to degrease the metal with an alcohol swab and apply a gel based red thread lock in the shaft opening before pressing in a new pin and that usually works fine:

https://www.amazon.com/Vibratite-Permanent-Anaerobic-Threadlocker-Milliliter/dp/B008RMTKUO

*** You'll need to apply heat later if you want to press a replacement pin

View attachment 10252

What do you run, now?

 

[Billl DeLong]

TEKNO is known for durability, in fact they tend to be more durable than most other brands on the market!

Unfortunately there aren't many Kyosho drivers at the club in my area so I can't provide any honest feedback on Kyosho durability.

I've bounced around many different brands where I ran TEKNO for the longest and I listed my specific reasons for going away from TEKNO here:
https://www.teknoforums.com/threads/build-review-eb48-2-0.1864/post-17986

Many of these issues have been addressed with the 2.1 release but another thing I missed on my list was that TEKNO's tend to be very hard on servos and I went through 3 servos on the 2.0 .... I often see other racers have servo failures as well, not sure what the deal is with that but the 2.1 is still hard on servos based on the local DNF's I've seen with this common failure.

I currently race an HB Racing E8WS:
https://www.rcgroups.com/forums/showthread.php?4464451-BUILD-REVIEW-HB-Racing-E8-WS

I feel it's equally as competitive as any other brand and arguably the most durable compared to 6 other brands ran locally. HB doesn't have any concerns with causing electronics to fail making it far less expensive to maintain which is very important to me.

Only concern with HB is that there was a mass exodus of team drivers recently as HB cut their payroll, but I've heard rumblings from other brands that they're also going to be cutting expenses for team drivers as well, I don't really think it's going to effect us drivers who are mere mortals, ha!

 

[Billl DeLong]

As luck will have it, I spotted a guy running practice laps on Friday with a Kyosho, he was a novice level driver and was really putting the car through a lot of abuse on the track, very rarely was he able to make a single lap without having to be marshaled. All I have to say is that I was extremely impressed with the durability over the 4 hour period of abuse I saw him put that car through!

I asked him what he thought of the car and he explained the only part he ever seems to break are the cast aluminum spindles at the kingpin hole. He says he breaks at least one of these every single time he come to the track to practice, but I have to imagine that an average sportsman level driver might rarely break that part.

Based on what I saw, I might say that Kyosho is on par with durability with HB.

Here's a video clip following Brandon Rose around the current layout which is probably one of the more difficult layouts I've seen at Thornhill:

https://www.flickr.com/gp/bill_delong/x70B487g53

 

[phm14]

As luck will have it, I spotted a guy running practice laps on Friday with a Kyosho, he was a novice level driver and was really putting the car through a lot of abuse on the track, very rarely was he able to make a single lap without having to be marshaled. All I have to say is that I was extremely impressed with the durability over the 4 hour period of abuse I saw him put that car through!

I asked him what he thought of the car and he explained the only part he ever seems to break are the cast aluminum spindles at the kingpin hole. He says he breaks at least one of these every single time he come to the track to practice, but I have to imagine that an average sportsman level driver might rarely break that part.

Based on what I saw, I might say that Kyosho is on par with durability with HB.


View attachment 10270
View attachment 10271


Here's a video clip following Brandon Rose around the current layout which is probably one of the more difficult layouts I've seen at Thornhill:

https://www.flickr.com/gp/bill_delong/x70B487g53

B Rose is in the flow, there. I ordered the K truggy kit late last week, due in Thursday. I have a XR8+/1900kV combo I'll be dropping in. Gulf Coast is doing a layout change this week. They have been running offroad, and oval, on a dual layout. I broke an ESC, in my freshly built EB48 2.1, mid summer, last year. Finally got the car back on the track last week, and it drove well for me. The nasty crashes tapered off, after some trigger time, and dropping from 4s to 3s. I was able to tighten my lines up, and may go ahead and throw in a transponder, for a baseline, on the new layout. Based on results with the K truggy, I may or may not build the Tekno truggy kit I have.

 

[Billl DeLong]

Didn't mean to mix match both, that Kyosho is not Brandon's car, as you know he runs SWorkz, I was trying to post a video showing the level of difficulty the track is currently to explain why that novice driver was wrecking his Kyosho so frequently.

You said truggy kit, but I've never seen a truggy motor that is 1900KV, can you confirm the can size is 4274?

I plan to race at Mike's for RC Pro in May in the eTruggy class, here's a recent photo from this past weekend for Thornhill's Series Round#3 where I took 1st and this will give you an idea of the popular brands on the podium:

1) HB
2) TEKNO
3) TLR
4) AE
5) TLR

*** HB should've also picked up 3rd but the other HB guy had a DNF in A1 with an electronic issue.

For RC Pro, I predict the following:
1) Smiley Henn - TEKNO
2) Chris Hatch -AE
3) Philo Hatch - TLR
4) Heath Evans - TEKNO (guy pictured 2nd in photo above)
5) Bill DeLong - HB (Mike's is typically low grip and I tend to do better with high grip so I may not even make the podium, ha!)